U.S. patent application number 11/598324 was filed with the patent office on 2008-05-15 for edge cutter assembly for use with a rotatable drum.
Invention is credited to Eric P. Helsel, Stephen P. Stiffler.
Application Number | 20080111418 11/598324 |
Document ID | / |
Family ID | 39368534 |
Filed Date | 2008-05-15 |
United States Patent
Application |
20080111418 |
Kind Code |
A1 |
Helsel; Eric P. ; et
al. |
May 15, 2008 |
Edge cutter assembly for use with a rotatable drum
Abstract
An edge cutter bit assembly for use in conjunction with a
rotatable drum having an edge. The edge cutter bit assembly
includes a holder that includes a plurality of bores wherein each
bores carries a chisel cutter bit so that the chisel cutter bit is
non-rotatable. The holder is oriented with respect to the drum so
that at least a portion of each one of the cutter bits extends past
the edge of the drum.
Inventors: |
Helsel; Eric P.; (New
Enterprise, PA) ; Stiffler; Stephen P.; (New
Enterprise, PA) |
Correspondence
Address: |
KENNAMETAL INC.
P.O. BOX 231, 1600 TECHNOLOGY WAY
LATROBE
PA
15650
US
|
Family ID: |
39368534 |
Appl. No.: |
11/598324 |
Filed: |
November 13, 2006 |
Current U.S.
Class: |
299/106 |
Current CPC
Class: |
B28D 1/188 20130101 |
Class at
Publication: |
299/106 |
International
Class: |
E21C 25/18 20060101
E21C025/18 |
Claims
1. An edge cutter bit assembly for use in conjunction with a
rotatable drum having an edge and a longitudinal surface, the edge
cutter bit assembly comprising: a holder containing a plurality of
bores wherein each bore carries a chisel cutter bit so that the
chisel cutter bit is non-rotatable; and the holder being oriented
with respect to the drum so that at least a portion of each one of
the cutter bits extends past the edge of the drum.
2. The edge cutter bit assembly of claim 1 wherein the holder
comprises a plurality of blocks, and each one of the blocks
containing one of the bores.
3. The edge cutter assembly of claim 2 wherein the holder comprises
a trio of the blocks, and the blocks being connected together.
4. The edge cutter bit assembly of claim 1 wherein the chisel
cutter bit having an axial forward end and an axial rearward end,
and the cutter bit having a head adjacent to the axial forward end
wherein the head carries a hard tip.
5. The edge cutter bit assembly of claim 4 wherein the chisel
cutter bit having a shank adjacent to the axial rearward end, and
the shank carries a resilient retainer that frictionally engages
the bore corresponding to the cutter bit.
6. The edge cutter bit assembly of claim 4 wherein the hard tip
comprises one of the group comprising cemented carbide and hard
particles embedded in a cast steel matrix.
7. The edge cutter bit assembly of claim 4 wherein the hard tip
presents a generally chisel-shaped cutting edge having a
thickness.
8. The edge cutter bit assembly of claim 4 wherein the hard tip
comprises a plurality of hard segments.
9. The edge cutter bit assembly of claim 1 wherein the holder
having a central longitudinal axis, and the holder being disposed
so that the central longitudinal axis is at an angle with respect
to a line normal to the longitudinal surface of the drum equal to
between about zero degrees and about thirty degrees.
10. The edge cutter bit assembly of claim 1 wherein the holder
having a central longitudinal axis, and the holder being disposed
so that the central longitudinal axis is at an angle with respect
to a line normal to the longitudinal surface of the drum equal to
between about five degrees and about fifteen degrees.
11. A rotatable drum assembly comprising: a drum having at least
one edge and a longitudinal surface; an edge cutter bit assembly
mounted to the surface of the drum; the edge cutter assembly
comprising: a holder containing a plurality of bores wherein each
bore carries a chisel cutter bit so that the chisel cutter bit is
non-rotatable; and the holder being oriented with respect to the
drum so that at least a portion of each one of the cutter bits
extends past the edge of the drum.
12. The rotatable drum assembly of claim 11 wherein the holder
comprises a plurality of blocks, and each one of the blocks
containing one of the bores.
13. The rotatable drum assembly of claim 12 wherein the holder
comprises a trio of the blocks, and the blocks being connected
together.
14. The rotatable drum assembly of claim 11 wherein the chisel
cutter bit having an axial forward end and an axial rearward end,
and the cutter bit having a head adjacent to the axial forward end
wherein the head carries a hard tip.
15. The rotatable drum assembly of claim 14 wherein the chisel
cutter bit having a shank adjacent to the axial rearward end, and
the shank carries a resilient retainer that frictionally engages
the bore corresponding to the cutter bit.
16. The rotatable drum assembly of claim 14 wherein the hard tip
comprises one of the group comprising cemented carbide and hard
particles embedded in a cast steel matrix.
17. The rotatable drum assembly of claim 14 wherein the hard tip
presents a generally chisel-shaped cutting edge having a
thickness.
18. The rotatable drum assembly of claim 14 wherein the hard tip
comprises a plurality of hard segments.
19. The rotatable drum assembly of claim 11 wherein the holder
having a central longitudinal axis, and the holder being disposed
so that the central longitudinal axis is at an angle with respect
to a line normal to the longitudinal surface of the drum equal to
between about zero degrees and about thirty degrees.
20. The rotatable drum assembly of claim 11 wherein the holder
having a central longitudinal axis, and the holder being disposed
so that the central longitudinal axis is at an angle with respect
to a line normal to the longitudinal surface of the drum equal to
between about zero degrees and about thirty degrees.
Description
BACKGROUND OF THE INVENTION
[0001] The invention pertains to an assembly that impinges the
earth strata such as, for example, asphaltic roadway material in a
road planing operation. More specifically, the invention pertains
to an improved assembly that impinges the earth strata (e.g.,
asphaltic roadway material) in such a fashion so as to exhibit an
improvement in the operational efficiency of the assembly.
[0002] Heretofore, it has been common practice to mill the surface
of a roadway, and especially a roadway made of asphaltic material.
Such a practice has been termed a road planing operation.
[0003] A road planing machine is used to perform the road planing
operation. Exemplary patent documents that describe road planing
machines include U.S. Pat. No. 6,457,779 B1 to Busley et al.; U.S.
Pat. No. 6,371,566 B1 to Haehn; U.S. Pat. No. 5,505,598 to Murray;
and U.S. Pat. No. 4,723,867 to Wirtgen.
[0004] A road planing machine includes a rotary road planing drum
that has opposite ends and a generally cylindrical surface. The
road planing drum is driven or powered by an engine whereby the
drum rotates about its longitudinal axis. The surface of the road
planing drum carries a plurality of blocks or holders. Each block
or holder carries a road planing bit wherein the axial forward end
of the bit has a hard carbide tip. Typically, the blocks or holders
are arranged in a helical pattern about the surface of the road
planing drum so as to, in essence, form a helical flight about the
surface of the drum.
[0005] In operation, the road planing drum is rotated under the
power of the engine so as to drive the hard carbide tip of the road
planing bit into the asphaltic material so as break up and
disintegrate the asphaltic material into smaller pieces or chunks
that one can term debris. The debris is fed into a conveyor located
in front of the drum and carried away from the location of the road
planing activity.
[0006] The pieces or chunks (i.e., debris) located near the
opposite ends of the drum may sometimes be trapped between the
opposite edge of the drum and the housing of the road planing
machine. In the past, in order to try to direct the debris past the
opposite edges back into the helical flights of the drum, drums
have exhibited edge cutter assemblies. An edge cutter assembly
comprised a block with three or four bores wherein each bore
contained a rotatable cutting bit. Each block has an orientation
such that it extends past the opposite edge of the road planing
drum so as to gather up the debris. While the use of such an edge
cutter assembly has provided satisfactory results, there remains a
need to provide an assembly such as, for example, a road planing
assembly that exhibits improved operational efficiency. The
improvement in operational efficiency can take place through an
increase in the ability of the edge cutter assembly to gather and
direct debris toward the helical flight.
[0007] During the road planing operation, it is not uncommon for
the opposite ends of the drum, as well as the main tool holders (or
blocks), to experience damage due to impingement against uncut
roadway material wherein the uncut roadway material essentially
defines the edge of the cutting path. Edge cutters function to cut
the sides of the cutting path of the road planing drum and thereby
protect the ends of the drum and the main tool holders from damage
due to impingement against the uncut roadway material. Edge cutters
also function to improve the quality of the cutting path by making
a straighter edge in the roadway material that defines the cutting
path.
[0008] Heretofore, the edge cutter assemblies have been useful to
protect the opposite edges from damage. As mentioned above, the
earlier edge cutter assembly comprised a block with three or four
bores wherein each bore contained a rotatable cutting bit. While
the use of such an edge cutter assembly has provided satisfactory
results, there remains a need to provide an assembly such as, for
example, a road planing assembly that exhibits improved ability to
protect the opposite edges of the road planing drum. The
improvement in protection can take place through an improved edge
cutter assembly.
[0009] It should be appreciated that although the above discussion
describes road planing machines, the present invention is also
applicable to other apparatus. For example, the present invention
is applicable to reclaimer (cold recycling) machines.
SUMMARY OF THE INVENTION
[0010] In one form thereof, the invention is an edge cutter bit
assembly for use in conjunction with a rotatable drum that has an
edge. The edge cutter bit assembly comprises a holder that contains
a plurality of bores Each one of the bores carries a chisel cutter
bit so that the chisel cutter bit is non-rotatable. The holder is
oriented with respect to the drum so that at least a portion of
each one of the cutter bits extends past the edge of the drum.
[0011] In still another form thereof, the invention is a rotatable
drum assembly that comprises a drum that has at least one edge and
a longitudinal surface. The assembly further includes an edge
cutter bit assembly mounted to the surface of the drum. The edge
cutter assembly comprises a holder that contains a plurality of
bores. Each one of the bores carries a chisel cutter bit so that
the chisel cutter bit is non-rotatable. The holder is oriented with
respect to the drum so that at least a portion of each one of the
cutter bits extends past the edge of the drum.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The following is a brief description of the drawings that
form a part of this patent application:
[0013] FIG. 1 is an isometric view of one edge of a road planing
drum wherein the drum contains a trio of edge cutter assemblies of
the present invention spaced about the surface of the edge at about
120 degrees apart;
[0014] FIG. 2 is an isometric view of one edge cutter assembly from
FIG. 1 wherein one of the cutter bits has been exploded away from
bore of its corresponding block;
[0015] FIG. 3 is an isometric view of the cutter bit of FIG. 2;
[0016] FIG. 4 is a side view of the cutter bit of FIG. 2;
[0017] FIG. 5 is a side view of one segment of the block or holder
of FIG. 2;
[0018] FIG. 6 is a front view of the segment of the block or holder
of FIG. 6; and
[0019] FIG. 7 is an isometric view of one edge of a PRIOR ART road
planing drum.
DETAILED DESCRIPTION OF THE INVENTION
[0020] FIG. 7 illustrates a PRIOR ART road planing drum assembly.
More specifically, this prior art assembly includes a road planing
drum that has a generally cylindrical surface and opposite edges.
The drum further has a plurality of blocks mounted thereto. Each
one of the blocks carries a rotatable cutting tool (or road planing
bit). The road planning drum assembly further includes an edge
cutter assembly. This edge cutter assembly includes a block, which
is mounted to the surface of the drum, that contains a trio of
bores wherein each bore carries a rotatable road planning bit. The
edge cutter assembly is disposed so that at least a portion thereof
extends past the edge of the road planing drum.
[0021] Referring to a specific embodiment of the invention (as
illustrated in FIGS. 1-6), FIG. 1 illustrates a specific embodiment
of a road planing drum assembly generally designated as 20. Road
planing drum assembly 20 includes a road planing drum 22 that has
opposite edges wherein one edge 24 is shown in FIG. 1. The drum 22
further includes a generally cylindrical surface 26, which extends
in a longitudinal direction so that one could term it as a
longitudinal surface.
[0022] The road planing drum assembly 20 further contains a
plurality of road planing bit-block assemblies (generally
designated as 28). Each road planing bit-block assembly 28 is
mounted to the surface 26 of the road planing drum 22 so as to
typically form a helical pattern or flight. The helical flight of
road planing bit-block assemblies 28 facilitates the transfer of
debris to a central location along the axial length of the drum as
will be described in more detail hereinafter.
[0023] The road planing drum assembly 20 further includes a
plurality of edge cutter assemblies generally designated as 40.
Although the number of these edge cutter assemblies 40 may vary
depending upon the circumstances, as illustrated in FIG. 1, there
is a trio of edge cutter assemblies 40. Referring to FIG. 1, each
edge cutter assembly 40 is located at the one edge 24 of the road
planing drum 22. Each edge cutter assembly 40 is spaced about 120
degrees apart about the circumference of the edge 24. As can be
seen (and as well be described in more detail hereinafter), the
orientation of each edge cutter assembly 40 is such so that it
extends (in the axial direction) past the one edge 24.
[0024] Each edge cutter assembly 40 comprises a holder 42. Holder
42 has a central longitudinal axis A-A (see FIG. 2). The holder 42
comprises a trio of block segments (44, 46 and 48) that are
structurally the same. One preferred block segment is a commercial
embodiment sold by Kennametal Inc. of Latrobe, Pa. 15650 under the
designation 87B Block (Part No. 1012275). Referring to block
segment 48 as an example for all of the block segments, block
segment 48 contains a central bore 50, which is defined by a bore
wall 56. Bore 50 has an axial forward end 52 and an axial rearward
end 54. The block segments (44, 46, 48) are joined together by
connector/spacers 60 and 62. More specifically, connector/spacer 60
joins together block segments 44 and 46 and connector/spacer 62
joins together block segments 46 and 48.
[0025] Holder 42 is mounted (e.g., by welding) to the surface 26 of
the drum 22. The orientation of the holder 42 is such that the
central longitudinal axis A-A of the holder is disposed at an angle
C with respect to a line (see line B-B in FIG. 2) perpendicular (or
normal) of the longitudinal surface 26 of the drum 22. In one
preferred embodiment, the holder 42 is disposed so that the central
longitudinal axis A-A thereof is at an angle C with respect to a
line (B-B) normal to the longitudinal surface of the drum equal to
between about zero degrees and about thirty degrees. In another
preferred embodiment, the holder 42 is disposed so that the central
longitudinal axis A-A thereof is at an angle C with respect to a
line (B-B) normal to the longitudinal surface of the drum equal to
between about five degrees and about fifteen degrees.
[0026] As can be seen in FIG. 2, at least a part of the assembly 40
extends past the edge 24 of the drum 22. As can be appreciated the
magnitude of the extension of the holder past the edge can vary
depending on a designed width that is more than the axial length of
the drum and less than the maximum cutting width of the road
planing drum.
[0027] Each edge cutter assembly 40 further includes a
non-rotatable chisel cutter bit generally designated as 70. One
cutter bit is a commercial embodiment sold by Kennametal Inc. of
Latrobe, Pa. 15650 under the designation AR150 87 Carbide-Edged
Tooth (Part No. 1012240). As is apparent from the description below
taken in conjunction with the relevant drawings, a chisel cutter
bit is a non-rotatable style of cutter bit that has a hard insert
adjacent to the axial forward end thereof. At least a portion of
the axial forward end of the hard insert presents a generally
chisel-shaped cutting edge. In this context, a generally
chisel-shaped cutting edge may comprise a sharp cutting edge.
Applicants further contemplate that a generally chisel-shaped
cutting edge may be defined by an edge that has some thickness. For
example, the chisel-shaped cutting edge can comprise a generally
planar or generally arcuate surface (or a combination thereof) that
has a thickness.
[0028] Cutter bit 70 has an elongate body 71 that has an axial
forward end 72 and an axial rearward end 74. There is a head
portion 76 adjacent to the axial forward end 72. The head portion
76 contains a notch 80 that receives therein a hard insert 77 so
that the head portion 76 carries the hard insert (or tip) 77. In
the specific embodiment, the hard insert 77 is made of a plurality
of hard insert segments 78. Each one of the hard insert segments 78
has a generally chisel-shaped cutting edge 79. In this specific
embodiment, the chisel-shaped cutting edge 79 has a thickness and
is arcuate. The hard insert 77 may be made of hard materials such
as, for example, tungsten carbide or cemented (cobalt) tungsten
carbide or carbide pieces embedded in a cast steel matrix. One
preferred composition for the tungsten carbide hard insert is
between about 6 weight percent to about 12 weight percent cobalt
with the balance tungsten carbide, except for impurities and
possibly minor additives. The cast hard insert can be made along
the lines of U.S. Pat. No. 4,608,318 to Makrides (assigned to
Kennametal Inc. of Latrobe, Pa.).
[0029] There is a shank portion 82 adjacent to the axial rearward
end 74. Shank portion 82 includes a reduced diameter section 84
that is defined so as to be between a frusto-conical shoulder 86
and a rearward shoulder 88. Axial rearward of the rearward shoulder
88 is a notch 92 that contains a groove 94.
[0030] The reduced diameter section 84 of the shank portion 82
carries a resilient retainer sleeve 98. The resilient retainer
sleeve 98 has an axial forward end 100 and an axial rearward end
102. The resilient retainer sleeve may have a structure and
properties along the line of the disclosure set forth in U.S. Pat.
No. 4,201,421 to Den Besten et al.
[0031] To assembly the cutter bit 70 to any block segment (and with
specific reference to block segment 48), the axial rearward end of
the cutter bit 70 is inserted into the axial forward end 52 of the
bore 50 until the frusto-conical shoulder contacts the portion of
the block segment 48 that surrounds the axial forward end 52 of the
bore 50. As is known in the art, the resilient retainer sleeve 98
expands against the bore wall 56 so as to frictionally engage the
bore wall 56. This frictional engagement retains the cutter bit 70
within the bore 50 of the block segment 48. Once the cutter bit 70
is positioned within the bore 50 of the block segment 48, a pin
(not illustrated) is used to engage the groove 94 so as to render
the cutter bit 70 non-rotatable as is well-known in the pertinent
art.
[0032] In operation, the road planing drum is rotated under the
power of the engine so as to drive the hard carbide tip of the road
planing bit into the asphaltic material so as break up and
disintegrate the asphaltic material into smaller pieces or chunks
that one can term debris. The debris is fed into a conveyor located
behind the drum and carried away from the location of the road
planing activity.
[0033] The pieces or chunks (i.e., debris) located near the
opposite ends of the drum may sometimes be trapped between the
opposite edge of the drum and the machine housing. In order to
direct the debris past the opposite edges back into the helical
flights of the drum, the drum contains the edge cutter assemblies.
As described above, each edge cutter assembly has a portion thereof
that extends past the opposite edge of the road planing drum so as
to contact and thereby gather up the scattered debris. As can be
appreciated, at least a portion of the hard insert of the chisel
cutter bit presents a generally planar (or flat) surface. By using
chisel cutter bits that have a generally planar surface geometry on
at least a portion thereof, the edge cutter assembly has exhibited
improved operational efficiency by an increase in the ability of
the edge cutter assembly to gather and direct debris toward the
helical flight.
[0034] As described above, during the road planing operation, it is
not uncommon for the opposite ends of the drum, as well as the main
tool holders (or blocks), to experience damage due to impingement
against uncut roadway material wherein the uncut roadway material
essentially defines the edge of the cutting path. By using edge
cutters that function to cut the sides of the cutting path of the
road planing drum, the ends of the drum and the main tool holders
are protected from damage due to impingement against the uncut
roadway material. Edge cutters also function to improve the quality
of the cutting path by making a straighter edge in the roadway
material that defines the cutting path.
[0035] The edge cutter assemblies have been useful to protect the
opposite edges from damage. By using chisel cutter bits that have a
generally planar surface geometry on at least a portion thereof,
the edge cutter assemblies exhibit an improved ability to protect
the opposite edges of the road planing drum.
[0036] The patents and other documents identified herein are hereby
incorporated by reference herein. Other embodiments of the
invention will be apparent to those skilled in the art from a
consideration of the specification or a practice of the invention
disclosed herein. It is intended that the specification and
examples are illustrative only and are not intended to be limiting
on the scope of the invention. The true scope and spirit of the
invention is indicated by the following claims.
* * * * *